Silent suction motor



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SILENT SUCTION MOTOR Filed sept. 19, 1945' ATTORNEYS Patented Oct. ll, 1949 SILENT SUCTION MOTOR Martin Bitzer, Kenmore, N. Y., assignor to Trico Products Corporation, Buffalo, N. Y.

Application September 19, 1945, Serial No. 617,336

5 Claims.

The invention relates in general to a iluid motor, and more particularly to a motor for propelling the cleaner blade used upon the windshield of a motor vehicle, and operated by suction derived from the motor of the vehicle. In

' suchv installations, the chamber at one side of the oscillating piston of the motor is connected to a source of suction and the other side ofthe piston is in open communication with the atmosphere through suitable inlet ports. As the atmospheric air enters the chamber, certain un desirable noises are produced, and foreign matter is likely to be drawn into the cylinder, thereby producing undue friction and wear.

The principal object of the invention has been to provide a fluid motor having improved air intake silencing means.

Another object has been to provide eiiicient iilter means so disposed as to be readily accessible for servicing when cleaning or when replacement becomes necessary. y

The above and other objects and advantages, which will become apparent as the description progresses, have been accomplished by the typical embodiment of the invention illustrated in the accompanying drawing, in which:

Fig. 1 is a side elevation of a well-known type of windshield cleaner motor embodying'` the invention, showing portions broken away for clearness of illustration;

Fig. 2 is an enlarged fragmentary plan View showing the iilter elements removed;

Fig. 3 is a, fragmentary sectional view of the motor taken on line III-HI of Fig. 2;

Fig. 4 is a fragmentary sectional elevation through the top plate of the motor taken on line IV-IV of Fig. 2 and showing the filter elements in place; and y Fig. 5 is a plan view of the filter element cover plate.

In the drawing, the motor is represented by the numeral I and is provided with a housing I I having a chamber I2 in which a piston I3 oscillates'. A top plate I4 is provided for the housing and is formed with a chamber I concentric with respect to the chamber I 2 for the accommodation of a portion of the piston I3. A valve chamber I9 is formed at one side of the motor by the outwardly projecting wall 20 and sealed to the atmosphere by iluid tight closure means 2I.

The motor` is provided with a nipple 22 for connection to a source of suction. The nipple communicates with a suction supply port 23 formed in a valve seat 24 in which latter is formed chamber ports 26 and 30 on opposite sides of the supply port for being alternately connectedthereto by means of an oscillating valve 25. The two chamber ports communicate with the motor chamber I2 at opposite sides of the piston and therefore when one side of the chamber is connected to the source of reduced pressure through the operation of the valve 25 the other side is in open communication with the atmosphere to actuate the piston. The valve 25 isshifted back and forth between its two operative positions by well-known automatic mechanism set in operation by the piston carrying shaft I6 as the piston oscillates under the pressure differential, a part of the mechanism being shown at 2B.

In prior constructionsthe air has entered the chamber I9 through restricted openings, as shown in Patent No. 2,032,319 granted February 25, 1936 to E. C. Horton and H. Hueber, or through relatively small filters, as 'shown in Patent No. 2,260,853 granted October 28, 1941 to H. C. Hueber.

The present invention contemplates a freer but quieter entrance of the atmospheric air into the motor. To this end a relatively large intake chamber 32 is formed by an upstanding wall 33 on the top plate I4. This Wall preferably extends around three sidesof the intake chamber which has an air intake 3'I at its open side. An upstanding lug 34 is provided at each end of the wall. A cover plate 35 is disposed on top of the wall 33, and it has a notch 36 at each forward corner for engagement with a respective one of the lugsl 34, whereby the plate may be conveniently registered with the wall and maintained in such position. A fastening screw 40 passes through an aperture 4I in the plate and into a screw threaded boss 43 on the top plate of the motor whereby the cover is securely held in position. Arranged across the open side 31 of the intake chamber 32 is a plurality of upstanding retaining pins 44 which serves to retain the filter body 45 in position. Such open side 31 which provides for the entrance of air into the intake chamber is of considerable size and is substantially unrestricted so that the air en. tering the chamber may not have its velocity materially increased. The pins 44 preferably extend upwardly to a point of contact with the cover plate 35.

Formed through or beneath the wall 33 adjacent the valve chamber I9 is an air inlet passage 46 which serves to connect the valve chamber with the intake chamber 32. This inlet pasisage is in open communication with an inlet I The fins at one side of the inlet channel extend from the wall 33, and at the opposite side from an upstanding partition l thereby providing opposing pairs of reentrant pockets 52 which function to silence or dampen the air noise as it rushes into the automatic valve chamber. These fins extend upwardly from the channel bottom and terminate short of the top surface of the wall 33 thereby providing a space 53 for the reception of an overlying and relatively thin fiat filter body 5l. The partition 5| is integral with the Wall 33 at the side adjacent the valve chamber, but is spaced from the opposite portion of the wall, whereby an entrance port 55\to the channel 43 is provided.

Additional air inlet openings 53 are formed in the cover plate 35 near the forward edge thereof whereby additional air is permitted to enter the suction supply chamber through the ilter element 54.

From the foregoing it will be obvious that ample openings are provided for the entrance of atmospheric air to and through the intake chamber 32, and ample filtering capacity is provided for the air entering the motor. Such air is passed through the inlet passage 5I and thence through the channel 49 and between the oppositely arranged flns 50. The air in passing through the silencer (parts 4S, 50, and 52) is silenced by reason of the opposed lateral pockets 52 and substantially all objectionable noises such as whistling or wheezing are avoided. The air after passing through the channel is drawn into the valve chamber through the air inlet passage I6, and there directed by the valve 25 of automatic mechanism into the chamber I2 on either side of the piston. The top plate I4 of the m'otor may be readily die cast with the silencer chamber 43 and its fins all in one unit. This tends toward economy in production and compactness of assembly.

While but one embodiment of the invention has been shown, it is obvious that the details of the device may be modified somewhat without departing from the spirit of the invention or the sco of the appended claims.

What is claimed is: e

1. In a suction operated motor, a casing chamber, with an air inlet chamber communicating therewith, filter means disposed within said inlet chamber, and a plurality of spaced oppositely disposed sound dampening pockets forming an inlet 4 channel connecting said inlet chamber to said valve chamber.

2. A fluid operated motor having a casing formed with a closed valve chamber, said casina having an air inlet chamber communicating with said valve chamber, opposed series of sound deadening pockets forming an exposed inlet channel connecting said inlet chamber with said valve chamber, and a cover plate secured over said opposed series of pockets and removable to give access to the pockets and to the channel defined thereby.

3.'A suction operated motor having a casing formed with a closed valve chamber and an air inlet chamber, a plurality of opposed air pockets arranged in sound dampening order between the two chambers for defining an air inlet channel connecting said inlet chamber with said valve chamber, a cover plate secured over and forming one side of said pockets, a filter pad disposed over said channel and beneath said plate, and a relatively larger filter element disposed within said inlet chamber in advance of the channel.

4. A fluid operated motor having a casing formed with a closed valve chamber and with an air inlet chamber, said inlet chamber being substantially rectangular and formed by upstanding walls on three sides, retaining pins extending across the open side of said inlet chamber, a filter element disposed within said inlet chamber behind the pins, and a plurality of spaced oppositely arranged silencer pockets forming an exposed inlet channel establlshing communication between said inlet chamber and said valve chamber.

5. In an air operated motor, two oppositely arranged seriesy of sound dampening pockets defining an air inlet channel for establishing communication between two chambers, a cover plate secured over said pockets for closing the one side thereof, said cover plate being formed with intake openings, and a filter pad disposed over said channel and beneath'said plate.

MARTIN BITZER.

REFERENCES CITED The following references are of record in the `le of this patent:

UNITED STATES PATENTS Number Name Date 2,260,853 Hueber Oct. 28, 1941 2,299,112 Schilling Oct. 20, 1942 

